The present invention relates to AC compressors and systems and methods for driving the AC compressor using an electric motor and an internal combustion engine.
Hybrid compressor systems having an electric motor and an internal combustion engine coupled to an AC compressor have gained widespread interest, especially in the automotive environment. Typically, an AC compressor is driven by an automobile""s engine during engine operation. When the engine is not operating, an electric motor is used to drive the compressor. Generally, the engine is coupled to the compressor through a drive belt and clutch mechanism. The electric motor, however, is typically coupled to the AC compressor via a solid shaft.
While conventional systems for driving AC compressors achieve their intended purpose, many problems still exist. For example, while the engine is operating and therefore driving the AC compressor, the electric motor being attached to the AC compressor through a solid shaft is also turning. The rotation of the electric motor while the AC compressor is driven by the engine not only decreases efficiency of the overall system by adding additional load on the engine but also increases wear of the electric motor.
Other problems not resolved by the prior art include having to choose from a limited selection of electric motors having a desired torque output to drive the AC compressor. Disadvantageously, the electric motor needed to develop the required torque is costly and adds significant weight to the vehicle.
Therefore, what is needed is a new and improved system and method for driving an AC compressor. The new and improved system and method must increase the efficiency of the overall system and reduce wear. Moreover, the new and improved system and method must reduce the torque requirements of the electric motor, thereby reducing cost and weight of the overall system.
In accordance with an aspect of the present invention, a new and improved system and method for driving an AC compressor is provided. The system and method of the present invention eliminates the problems stated above by introducing a clutch mechanism between an electric motor and an AC compressor.
In accordance with another aspect of the present invention, a system for driving a compressor is provided. The system has an internal combustion engine in communication with the compressor for selectively driving an input shaft of the compressor, an electric motor in communication with the compressor for selectively driving the compressor when the compressor is not being driven by the engine, and a gear assembly operatively connected to a motor output of the electric motor shaft for changing a rotational speed of the motor output shaft.
In accordance with another aspect of the present invention, further having a clutch positioned between the gear assembly and the compressor for decoupling the compressor from the motor when the engine is driving the compressor.
In accordance with yet another aspect of the present invention, the clutch is a one-way clutch.
In accordance with yet another aspect of the present invention, the clutch is an electric clutch.
In accordance with yet another aspect of the present invention, the gear assembly further comprises a sun gear and a planetary gear.
In accordance with yet another aspect of the present invention, the sun gear is fixed to the motor output shaft.
In accordance with yet another aspect of the present invention, the gear assembly further includes a planetary gear carrier.
In accordance with yet another aspect of the present invention, the planetary gear is rotatably fixed to the carrier.
In accordance with yet another aspect of the present invention, the carrier is fixed to a stationary gear case that houses the gear assembly.
In accordance with yet another aspect of the present invention, a ring gear wherein the ring gear is fixed to the compressor input shaft.
In accordance with yet another aspect of the present invention, the carrier is configured for slideable engagement with the ring gear.
In accordance with yet another aspect of the present invention, a system for driving a compressor is provided. The system has an internal combustion engine, an electric motor, a gear assembly, and a clutch. The internal combustion engine is in communication with a compressor for selectively driving an input shaft of the compressor. The electric motor is in communication with the compressor for selectively driving the compressor when the compressor is not being driven by the engine. The gear assembly is operatively connected to a motor output shaft of the electric motor for changing a rotational speed of the motor output shaft. The clutch is positioned between the gear assembly and the compressor for decoupling the compressor from the motor when the engine is driving the compressor.
Further objects, features and advantages of the invention will become apparent from consideration of the following description and the appended claims when taken in connection with the accompanying drawings.